Bag slitting machines

ABSTRACT

A bag slitting machine comprising spaced support means adapted to engage opposite ends of a bag to support same over a discharge opening located between said spaced support means, slitting blade means arranged to traverse said discharge opening and adapted to slit the underside of a bag when so supported, and means for alternately raising and moving towards one another and lowering and moving away from one another said support means a number of times to promote the flow of the contents of said bag through said discharge opening.

[ 51 Aug. 1, 1972 United States Patent Poulton [5 1 BAG SLITTINGMACHINES Primary Examiner-Gerald M. Forlenza Assistant Examiner-LawrenceJ. Oresky Att0rney--Norris & Bateman [72] Inventor: Barrie ArmstrongPoulton,

Stockport, England [73] Assignee: Simon Handling Engineers Limited [57]ABSTRACT A bag slitting machine comprising spaced support means adaptedto engage opposite ends of a bag to [22] Filed: March 20, 1970 [21]Appl. No.: 21,390

support same over a discharge opening located between said spacedsupport means, slitting blade means arranged to traverse said dischargeopening and adapted to slit the underside of a bag when so sup- [30]Foreign Application Priority Data April 2, 1969 GreatBritain.............

ported, and means for alternately raising and moving towards one anotherand lowering and moving away from one another said support means anumber of times to promote the flow. of the contents of said bag throughsaid discharge opening.

80 00 5 W6 2 MB BM 4 1 .m Lm G St Um 1L 21 55 [58] Field of ReferencesCited UNITED STATES PATENTS 3,482,718 12/1969Moriarty............'........

8 Claims, 2 Drawing figures BAG SLITTING MACHINES This inventionconcerns bag slitting machines for opening bags to enable the contentsthereof to be empne It has been proposed for a bag opening and emptyingmachine to provide a slit in the bag and to promote the flow of materialfrom the bag by vibration. Experiments have shown that this method isnot satisfactory for certain materials which are difficult to handle andthat a much more positive method of promoting flow of material from thebag is required.

According to the present invention, a bag slitting machine comprisesspaced support means adapted to engage opposite ends of a bag to supportsame over a discharge opening located between said spaced support means,slitting blade means arranged to traverse said discharge opening andadapted to slit the underside of a bag when so supported, and means foralternately raising and moving towards one another and lowering andmoving away from one another said spaced support means a number of timesto promote the flow of the contents of said bag through said dischargeopening.

The invention will be further apparent from the following descriptionwith reference to the figures of the accompanying drawing, which show,by way of example only, one form of bag slitting machine embodying theinvention.

Of the drawing:

F IG. 1 shows a partly cut-away perspective view of the machine from thefront and FIG. 2 shows a plan view of part of the mechanism of themachine of FIG. 1.

Referring now to the drawing, it will be seen that the machine includesspaced support plates and 11, which in their normal position (FIG. 1)are inclined towards one another to define a bed of shallow V- shapedconfiguration. Between and below the plates 10 and 11 is a hopper 12having a discharge opening 13 at its lower extremity for delivery ofmaterial from bags emptied by the machine. The plates 10 and 11 arerespectively carried by pairs of arms 14 and 15 which are pivotallyconnected with fixed frame members at their lower ends. The arms 14 maybe raised and lowered by a double-acting pneumatic cylinder 16 and thearms 15 are connected for movement with the arms 14 by intermeshingequal gear wheels 17 and 18 secured to the arms 14 and 15 respectively.

Between the plates 10 and l l and over the hopper 12 are upwardlyprojecting knife blades 19 and 20 carried on pivoted arms 21 and 22which may be moved by double-acting pneumatic cylinders 23 and 24.

In use, a bag which is to be opened and emptied is placed on a loadingtable 25. The weight of the bag operates a micro-switch 26 which startsthe machine cycle. The table is first pivoted forwardly under the actionof a pneumatic cylinder 27 to throw the bag onto the bed of the machinewhere it is impaled on the knife blades 19 and 20 and on upwardlyprojecting spikes 28 provided on the support plates 10 and 11. Thecylinders 23 and 24 are then operated to cause the knife blades 19 and20 to separate generally transversely of the bag to slit its underside.A stirrup member 29 is then swung under the action of a pneumaticcylinder 30 in clockwise direction so that its central web is impactedwith the upper surface of the bag over the slit in its underside beforebeing returned in counterclockwise direction toits initial position.This operation causes a weakening of the bag in its central region andcauses material in the vicinity of the slit to flow from the bag andfall into the hopper 12, thereby facilitating subsequent operations aswill now be described.

The cylinder 16 is reciprocated a predetermined number of times to causethe plates 10 and 11 alternately to move upwardly andtowards one anotherand downwardly and away from one another a like number of times. Theends of the bag which are supported on the two plates thus move in asimilar fashion, the bag thus being alternately folded and unfoldedabout its center. This operation promotes the flow of the entirecontents of the bag through the slit in its underside and into thehopper 12.

When the bag has emptied a stirrup member 31 which normally lies in ahorizontal plane over the hopper is swung upwardly under the action of apneumatic cylinder 32 to engage the empty bag and throw it clear of themachine.

Finally the member 31 and knife blades 19 and 20 are returned to theirinitial positions in readiness for the next machine cycle.

It will be appreciated that it is not intended to limit the invention tothe above example only, many variations, such as might readily occur toone skilled in the art, being possible without departing from the scopethereof.

. For example, with certain materials which are highly flowable it mayonly be necessary to raise and lower the support plates once in eachmachine cycle.

What is claimed is:

1. A bag slitting machine comprising spaced support means havingupwardly directed spikes and adapted to engage opposite ends of a bag tosupport said bag over a discharge opening located between said spacedsupport means, means mounting said support means for rotational movementabout axes lying below and inwardly of same, slitting blade meansadapted to slit the underside of a bag when so supported, said slittingblade means comprising two upwardly projecting blades which in oneposition are disposed adjacent one another centrally over the dischargeopening and which impale a bag positioned on the machine and whichseparate from one another for the purpose of slitting the underside ofthe bag, and means for alternately raising and moving towards oneanother and lowering and moving away from one another said support meansa plurality of times to promote the flow of the contents of said bagthrough said discharge opening, said support means being inclinedtowards one another when at their lowermost positions to define a bed ofshallow V- shaped configuration for supporting a bag.

2. A bag slitting machine according to claim 1 including means adaptedto deliver an impact to the upper surface of the bag after it has beenslit and before said support means are raised and lowered.

3. A bag slitting machine according to claim 2 including a stirrupmember surrounding the field of movement of the slitting blade means andadapted to be swung from a generally horizontal position upwardly forthe purposes of discharging a bag which has been emptied.

4. A bag slitting machine according to claim 3 including a pivotallymounted feed table adapted to receive a bag to be opened and emptied andto tip same onto the support members of the machine.

5. A bag slitting machine comprising spaced support means adapted toengage opposite ends of a bag to support same over a discharge openinglocated between said spaced support means, slitting blade means arrangedto traverse said discharge opening and adapted to slit the underside ofa bag when so supported, and means for alternately raising and movingtowards one another and lowering and moving away from one another saidsupport means a number of times to promote the flow of the contents ofsaid bag through said discharge opening, said slitting blade meanscomprising two upwardly projecting blades which in one position aredisposed adjacent one another centrally over the discharge opening andwhich impale a bag positioned on the machine and which separate from oneanother for the purpose of slitting the underside of said spaced supportmeans, slitting blade means arranged to traverse said discharge openingand adapted to slit the underside of a bag when so supported, means foralternately raising and moving towards one another and lowering andmoving away from one another said support means a number of times topromote the flow of the contents of said bag through said dischargeopening, and means adapted to deliver an impact to the upper surface ofthe bag after it has been slit and before said support means are raisedand lowered.

7. A bag opening and emptying machine comprising spaced members forsupporting opposite ends of a bag, bag slitting means disposed betweensaid members, means for actuating said bag slitting means for openingthe underside of a bag on said support members, means for repeatedlyrocking said members about substantially parallel axes forcorrespondingly repeatedly folding and unfolding said bag while it isdischarging through its slitted opening, and means for sequentiallyimpacting the upper side of said bag after the underside has beenslitted.

8. The bag opening and emptying machine defined in claim 7, wherein saidmembers are cyclically alternately moved upwardly and towards oneanother and downwardly and away from one another.

1. A bag slitting machine comprising spaced support means havingupwardly directed spikes and adapted to engage opposite ends of a bag tosupport said bag over a discharge opening located between said spacedsupport means, means mounting said support means for rotational movementabout axes lying below and inwardly of same, slitting blade meansadapted to slit the underside of a bag when so supported, said slittingblade means comprising two upwardly projecting blades which in oneposition are disposed adjacent one another centrally over the dischargeopening and which impale a bag positioned on the machine and whichseparate from one another for the purpose of slitting the underside ofthe bag, and means for alternately raising and moving towards oneanother and lowering and moving away from one another said support meansa plurality of times to promote the flow of the contents of said bagthrough said discharge opening, said support means being inclinedtowards one another when at their lowermost positions to define a bed ofshallow V-shaped configuration for supporting a bag.
 2. A bag slittingmachine according to claim 1 including means adapted to deliver animpact to the upper surface of the bag after it has been slit and beforesaid support means are raised and lowered.
 3. A bag slitting machineaccording to claim 2 including a stirrup member surrounding the field ofmovement of the slitting blade means and adapted to be swung from agenerally horizontal position upwardly for the purposes of discharging abag which has been emptied.
 4. A bag slitting machine according to claim3 including a pivotally mounted feed table adapted to receive a bag tobe opened and emptied and to tip same onto the support members of themachine.
 5. A bag slitting machine comprising spaced support meansadapted to engage opposite ends of a bag to support same over adischarge opening located between said spaced support means, slittingblade means arranged to traverse said discharge opening and adapted toslit the underside of a bag when so supported, and means for alternatelyraising and moving towards one another and lowering and moving away fromone another said support means a number of times to promote the flow ofthe contentS of said bag through said discharge opening, said slittingblade means comprising two upwardly projecting blades which in oneposition are disposed adjacent one another centrally over the dischargeopening and which impale a bag positioned on the machine and whichseparate from one another for the purpose of slitting the underside ofthe bag.
 6. A bag slitting machine comprising spaced support meansadapted to engage opposite ends of a bag to support same over adischarge opening located between said spaced support means, slittingblade means arranged to traverse said discharge opening and adapted toslit the underside of a bag when so supported, means for alternatelyraising and moving towards one another and lowering and moving away fromone another said support means a number of times to promote the flow ofthe contents of said bag through said discharge opening, and meansadapted to deliver an impact to the upper surface of the bag after ithas been slit and before said support means are raised and lowered.
 7. Abag opening and emptying machine comprising spaced members forsupporting opposite ends of a bag, bag slitting means disposed betweensaid members, means for actuating said bag slitting means for openingthe underside of a bag on said support members, means for repeatedlyrocking said members about substantially parallel axes forcorrespondingly repeatedly folding and unfolding said bag while it isdischarging through its slitted opening, and means for sequentiallyimpacting the upper side of said bag after the underside has beenslitted.
 8. The bag opening and emptying machine defined in claim 7,wherein said members are cyclically alternately moved upwardly andtowards one another and downwardly and away from one another.